tda7088t
Look at Philips TDA7088T
TDA7088T has auto tune feature(like digital tunning)
The radio which used 7088T is about 1usd
Equipped with all stages of a mono receiver from
antenna to audio output
· Mute circuit
· Search tuning with a single varicap diode
· Mechanical tuning with integrating AFC
· AM application supported
· Power supply polarity protection
· Power supply voltage down to 1.8
The TDA7088T is a bipolar integrated circuit for use in mono portable and pocket radios. It is used when a minimum of peripheral components (of small dimensions and low costs) is important. The circuit contains a frequency-locked-loop (FLL) system with an Intermediate Frequency (IF) of about 70 kHz. Selectivity is achieved by active RC-filters. De-tuning related to the IF and too weak input signals is suppress
example application hxxp://www.mikroelektronika.co.yu/english/product/books/rrbook/chapter4/chapter4c.htm
or
Philips TEA5777
The TEA5777 combines high quality AM/FM performance with
unmatched reduction in application size and bill of materials.
Easy to design in, it is the first device to enable the integration
of AM/FM reception into portable devices like mobile phones
and PDAs.
Enjoy